Influence of Dexamethasone on Atrial Ion Currents and Their Early Ionic Tachycardia-induced Electrical Remodeling in Rabbits
| Autor: | Roman Laszlo, Mareike Schwiebert, Karen Anna Menzel, Ralph F. Bosch, Birgit Schreiner, Christian Eick, Juergen Schreieck |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Tachycardia
medicine.medical_specialty Time Factors Physiology Anti-Inflammatory Agents Inflammation Dexamethasone Internal medicine Atrial Fibrillation medicine Animals Electrical Remodeling Heart Atria cardiovascular diseases Patch clamp business.industry Atrial fibrillation medicine.disease Pathophysiology Electrophysiological Phenomena Endocrinology cardiovascular system Rabbit model Rabbits medicine.symptom business medicine.drug |
| Zdroj: | Cellular Physiology and Biochemistry. 26:495-502 |
| ISSN: | 1421-9778 1015-8987 |
| Popis: | Background: Certain evidence points to a role of inflammation in AF pathophysiology. Thus, antiinflammatory treatment of AF is discussed. Effects of a dexamethasone treatment (7 days) on atrial ion currents (ICa,L, Ito, Isus) and their tachycardia-induced remodeling were studied in a rabbit model. Methods: 6 groups of 4 animals each were built. Rapid atrial pacing (600 min) was performed for 24 and 120 hours with/ without dexamethasone treatment. Ion currents were measured using whole cell patch clamp method. Results: Rapid atrial pacing reduced (ICa,L, Ito was decreased after 24 hours but almost returned to control values after 120 hours. When dexamethasone-treated animals also underwent atrial tachypacing, pacing-induced reduction of ICa,L was still observed after 24 hours and was even augmented after 120 hours compared to untreated but tachypaced animals. Ito was not influenced by dexamethasone alone. In dexamethasone-treated animals, reduction of Ito was not observed after 24 hours but occurred after 120 hours of atrial tachypacing. Isus was neither influenced by rapid atrial pacing nor by dexamethasone. Biophysical properties of all currents were affected neither by rapid atrial pacing nor by dexamethasone. Conclusion: Dexamethasone influenced tachycardia-induced alterations of atrial Ito. Our experiments give evidence that - amongst other anti-inflammatory action – impact of dexamethasone on ion currents and their tachycardia-induced alterations might also play a role in treatment/prevention of AF with steroids. |
| Databáze: | OpenAIRE |
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